Evaporation rate of water in a vessel

The evaporation rate of water in a vessel was studied as a function of of temperature, humidity, air velocity, and diameter of the vessel. The atmospheric temperature was varied between 14 and 29 °C, the humidity between 24% and 75%, the air velocity between 0.09 and 7.9 m/s, and the diameter between 5.6 and 12.4 cm. The experimental results are compared with a theory that is based on the idea that the evaporation rate is equal to the diffusion rate of water vapor through the boundary layer covering the water surface in a vessel. In order to compare the experimental evaporation rate with the theory, the temperature of the water surface was carefully measured with a thin thermocouple. The agreement between the present experiments and the theory is generally good.